Okay, I've just tried the latest free Dot-a-Pix puzzle (ID: 05390100440), but found a bug, both dots #140 and #141 are end-dots, thus dot #141 can't be connected to anything, making the puzzle uncompletable.

We fixed the bug in the puzzle. You are welcome to test and let us know if there are still any problems. Note that this procedure required removing saved data, so we're sorry if you were in the middle of solving this puzzle.